BKTSX vs. BASMX
BKTSX (iShares Total U.S. Stock Market Index Fund Class K) and BASMX (iShares Total U.S. Stock Market Index Fund Investor A Shares) are both Large Cap Blend Equities funds from iShares tracking the Russell 3000 Index. Both are passively managed. Over the past 10 years, BKTSX returned 15.31%/yr vs 14.96%/yr for BASMX. With a 1.00 correlation, they move nearly in lockstep. BKTSX charges 0.02%/yr vs 0.33%/yr for BASMX.
Performance
BKTSX vs. BASMX - Performance Comparison
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Returns By Period
The year-to-date returns for both stocks are quite close, with BKTSX having a 10.08% return and BASMX slightly lower at 9.92%. Both investments have delivered pretty close results over the past 10 years, with BKTSX having a 15.31% annualized return and BASMX not far behind at 14.96%.
BKTSX
- 1D
- -0.32%
- 1M
- 0.47%
- YTD
- 10.08%
- 6M
- 8.96%
- 1Y
- 25.53%
- 3Y*
- 21.13%
- 5Y*
- 12.46%
- 10Y*
- 15.31%
BASMX
- 1D
- -0.32%
- 1M
- 0.44%
- YTD
- 9.92%
- 6M
- 8.79%
- 1Y
- 25.13%
- 3Y*
- 20.74%
- 5Y*
- 12.12%
- 10Y*
- 14.96%
BKTSX vs. BASMX - Yearly Performance Comparison
| 2026 (YTD) | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | |
|---|---|---|---|---|---|---|---|---|---|---|
BKTSX iShares Total U.S. Stock Market Index Fund Class K | 10.08% | 17.15% | 23.83% | 26.02% | -19.05% | 25.56% | 20.82% | 31.12% | -5.37% | 21.02% |
BASMX iShares Total U.S. Stock Market Index Fund Investor A Shares | 9.92% | 16.81% | 23.46% | 25.63% | -19.32% | 25.26% | 20.37% | 30.71% | -5.57% | 20.65% |
Correlation
The correlation between BKTSX and BASMX is 1.00 - these two move nearly in lockstep. At this level, holding both provides almost no diversification benefit. If you already own one, adding the other does little to reduce portfolio risk.
| Correlation | |
|---|---|
Correlation (1Y) Calculated over the trailing 1-year period | 1.00 |
Correlation (3Y) Calculated over the trailing 3-year period | 1.00 |
Correlation (5Y) Calculated over the trailing 5-year period | 1.00 |
Correlation (10Y) Calculated over the trailing 10-year period | 1.00 |
Correlation (All Time) Calculated using the full available price history since Jan 4, 2016 | 1.00 |
The correlation between BKTSX and BASMX has been stable across timeframes, ranging from 1.00 to 1.00 - a consistent structural relationship.
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Return for Risk
BKTSX vs. BASMX — Risk / Return Rank
BKTSX
BASMX
BKTSX vs. BASMX - Risk-Adjusted Trends Comparison
This table presents a comparison of risk-adjusted performance metrics for iShares Total U.S. Stock Market Index Fund Class K (BKTSX) and iShares Total U.S. Stock Market Index Fund Investor A Shares (BASMX). Risk-adjusted metrics are performance indicators that assess an investment's returns in relation to its risk, enabling a more accurate comparison of different investment options.
Values are calculated on a 1-year rolling basis and updated daily. Risk-adjusted metrics are more stable over longer periods — use the period switch above to explore them.
| BKTSX | BASMX | Difference | |
|---|---|---|---|
| Sharpe ratioReturn per unit of total volatility | +0.03 | ||
| Sortino ratioReturn per unit of downside risk | +0.04 | ||
| Omega ratioGain probability vs. loss probability | 1.38 | 1.37 | +0.01 |
| Calmar ratioReturn relative to maximum drawdown | 3.03 | 2.97 | +0.06 |
| Martin ratioReturn relative to average drawdown | 13.51 | 13.21 | +0.30 |
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Drawdowns
BKTSX vs. BASMX - Drawdown Comparison
The maximum BKTSX drawdown since its inception was -34.97%, roughly equal to the maximum BASMX drawdown of -34.95%. Use the drawdown chart below to compare losses from any high point for BKTSX and BASMX.
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Drawdown Indicators
| BKTSX | BASMX | Difference | |
|---|---|---|---|
Max DrawdownLargest peak-to-trough decline | -34.97% | -34.95% | -0.02% |
Max Drawdown (1Y)Largest decline over 1 year | -8.87% | -8.92% | +0.05% |
Max Drawdown (3Y)Largest decline over 3 years | -19.29% | -19.32% | +0.03% |
Max Drawdown (5Y)Largest decline over 5 years | -24.98% | -25.12% | +0.14% |
Max Drawdown (10Y)Largest decline over 10 years | -34.97% | -34.95% | -0.02% |
Current DrawdownCurrent decline from peak | -1.47% | -1.51% | +0.04% |
Average DrawdownAverage peak-to-trough decline | -4.51% | -4.58% | +0.07% |
Ulcer IndexDepth and duration of drawdowns from previous peaks | 1.98% | 2.00% | -0.02% |
Volatility
BKTSX vs. BASMX - Volatility Comparison
iShares Total U.S. Stock Market Index Fund Class K (BKTSX) and iShares Total U.S. Stock Market Index Fund Investor A Shares (BASMX) have volatilities of 4.70% and 4.74%, respectively, indicating that both stocks experience similar levels of price fluctuations. This suggests that the risk associated with both stocks, as measured by volatility, is nearly the same. The chart below showcases a comparison of their rolling one-month volatility.
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Volatility by Period
| BKTSX | BASMX | Difference | |
|---|---|---|---|
Volatility (1M)Calculated over the trailing 1-month period | 4.70% | 4.74% | -0.04% |
Volatility (6M)Calculated over the trailing 6-month period | 9.97% | 10.00% | -0.03% |
Volatility (1Y)Calculated over the trailing 1-year period | 12.76% | 12.77% | -0.01% |
Volatility (5Y)Calculated over the trailing 5-year period, annualized | 17.45% | 17.47% | -0.02% |
Volatility (10Y)Calculated over the trailing 10-year period, annualized | 18.46% | 18.45% | +0.01% |
BKTSX vs. BASMX - Expense Ratio Comparison
BKTSX has a 0.02% expense ratio, which is lower than BASMX's 0.33% expense ratio.
Dividends
BKTSX vs. BASMX - Dividend Comparison
BKTSX's dividend yield for the trailing twelve months is around 1.06%, more than BASMX's 0.79% yield.
| Position | TTM | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
|---|---|---|---|---|---|---|---|---|---|---|---|
BASMX iShares Total U.S. Stock Market Index Fund Investor A Shares | 0.79% | 0.86% | 0.99% | 1.19% | 1.33% | 1.33% | 1.20% | 1.90% | 2.18% | 1.93% | 1.37% |
BKTSX iShares Total U.S. Stock Market Index Fund Class K | 1.06% | 1.14% | 1.27% | 1.46% | 1.64% | 1.58% | 1.51% | 2.15% | 2.49% | 2.17% | 1.54% |
Frequently Asked Questions
With a correlation of 1.00, BKTSX and BASMX move almost identically. Holding both adds very little diversification - you're essentially doubling your position in the same market segment. Choosing one is usually more capital-efficient.
BASMX has higher volatility (4.74%) compared to BKTSX (4.70%). In terms of maximum drawdown, BKTSX dropped -34.97% vs BASMX's -34.95%.
BKTSX currently has the higher Sharpe Ratio (2.11 vs 2.08), meaning it's delivered slightly more return per unit of risk over the trailing 12 months. However, this ranking shifts over time - use the Risk/Return Score above for a more comprehensive view that combines Sharpe, Sortino, and other measures used by quantitative funds.
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